There is an increasing interest in monitoring energy consumption and production. One of the quantities of interest is electricity consumption and production. Many have an interest in knowing how much electricity is used by electrical devices, or which circuit within an electrical system or within a region such as a commercial or residential building is supporting those electrical devices. Others may wish to track how much electricity is begin produced by a photovoltaic array (PVA) system on a building rooftop. Still others may wish to receive insight based on electricity usage, such as which appliances or machinery are operating, and when and for how long. One approach to knowing electricity consumption and production is to measure the electric current demanded by these circuits. Of particular interest is measuring alternating electric current (AEC) as it is a primary means of electricity transmission and delivery over long distances in public electric systems and national power grids. AEC is typically used in the distribution of electricity within commercial and residential buildings, and indicates the electricity is changing amplitude over time, often in a cyclical or sinusoidal manner.
Conventional monitoring systems for monitoring AEC require direct electrical connection to each circuit, splicing into the flow of electricity in each circuit, positioning of a measurement coil around the transmission line or wire in each circuit, or adding a sensor to electric outlets at each point where electric equipment is located throughout a residence or a commercial building. These conventional monitoring systems have inherent limitations, some of which include a high cost of the system, a high cost of installation, a high risk of injury to the installer while installing the system, and the need for modification or disruption to each circuit being monitored during installation. Recent methods for non-contact electricity monitoring include expensive, specialized sensors and complex placement procedures to ensure practical measurement of each circuit. Overcoming these limitations may enable much greater use of electricity consumption and production monitoring.